I've been working on a design that follows Rick's first board design (thanks for putting it together!), and I got some prototypes made for my won design that follows the reference. However, I can't get the board to to power on, and I've been trouble shooting for a couple days now. I'm at a loss, and I think I may be overlooking something. Would anyone be able to sanity check the attached schematic and board layout PDF? Hopefully the issue is just a cold solder joint somewhere 
I don't see anything obviously wrong with the schematic.
Are the 5V and 3V3 rails powered?
Yes, when I connect a USB-C cable, the pin to the P2 is getting 3V3, and the 5volt rail is getting 5volts. It's very weird. I also tried two different board and two different P2 modules.
Not sure why it's not booting.
- Looks like all 3V3 lines are connected.
- Nothing connected to the boot mode pins, such as TX, that prevent booting.
- The LED is common anode (though this just causes the colors to invert, not turn on, if you use a common cathode).
I really have no idea what's wrong, so more random questions:
- You have voltage, but is it drawing current?
- Is it showing up as a USB device (in case the problem is with the LED)
- What is the LED current? The maximum drive strength on the RGB pins is 4 mA per pin.
Not sure if it's drawing current, let me double check by connecting the 3V3 coming off the TI 62026 and the 3V3 Pin to the P2 in series.
It is not showing up as a USB device. I went to Device Restore USB | Tools | Particle, clicked the button, and nothing came up. I've also checked my USB cable to ensure it has all the data and power pins (it does).
The LED current is 25mA? I think I'm reading this right (chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://atta.szlcsc.com/upload/public/pdf/source/20211124/D13689C8DD74B55DEF49F36415B1D3D6.pdf)
The P2 definitely won't drive a 25mA LED, so that could be a problem. You'd need to add a transistor driver for that. The first board example uses a 1 mA (per color) RGB LED.
But it probably still should boot, it just won't display LED colors.
So it's drawing around 100mA, between the 3V3 out of the TI 62026 and one of the 3V3 legs of the capacitor going to the power in pin of the P2.
So it's doing something, that's slightly more than the normal idle current but close enough.
It's not connecting to the cloud, but it wouldn't because there are no Wi-Fi credentials, so that's probably normal.
The LED may not be working because it's drawing too much current. But USB should still work, so that's a bit confusing.
If you have a BLE scanner app you could check to see if it's advertising BLE for BLE provisioning of Wi-Fi.
Tried the BLE with no luck. I'm dumbfounded lol
I tried soldering two more boards, and they weren't drawing any current 
If you can remove the LED from one of your board, or remove the three current limiting resistors, that might be a good test to see if the excess current draw from the LED is causing issues. The device will run without an RGB LED, but of course it will be hard to tell what it's doing.
Your reset switch looks correct, but just to be sure, probe pad 34 and make sure it's high. Once I accidentally wired the ground to the equivalent to your pin 2 and the device would not boot because it was stuck in reset as it was always low regardless of whether the button was pressed.
I removed the LED with no luck. However, I think I may have found the issue. For some reason, pins 4, 6, 9, and 10 on the TI62026 weren't connected to the ground plane, and the pad (pin 11) also wasn't connected to ground. This would explain why the P2 wasn't turning on? When I connected the ground pin and the 3V3 power pin of the P2 in series to test current, it started to rise above 100mA, into 162 and 172mA, which I guess fried the board?
In any case, I scratched off the solder mask on one of the floating ground pins on the TI62026 and soldered it to the ground plane. But this didn't yield any results, which is interesting. I ordered new boards from Oshpark last night which has all the ground pins on the TI62026 actually connecting to ground.
It's hard to say for sure, but the module can draw up to 500 mA so 162 mA isn't that surprising. It's more than it would normally consume at idle, but during boot it's not exactly at idle either. But module damage would explain the no LED, no USB, and no BLE.
Fair point. I'll post an update, once those new boards arrive.